In the past, to impart a runflat capability enabling a tire to be driven on over a predetermined distance even if rapidly falling in internal pressure due to a puncture, burst, etc., for example, as shown in FIG. 1, there has been known a safety tire in which a reinforcing rubber 5 in the shape of crescent is inserted between a carcass 3 and an inner liner layer 4 in the side wall part 2 of a pneumatic tire 1. Note that, in FIG. 1, 6 indicates a cap tread, 7 indicates a bead filler, 8 indicates a belt layer and 9 indicates a bead. To enable the tire to be driven on even with a puncture by this configuration, it is sufficient to make the reinforcing rubber layer 5 a certain thickness or more. However, the reinforcing rubber layer 5 is too thick, there was the problem that the weight is increased. Further, if driven on in a state with the air expelled, the side part 2 will greatly flex and heat will build up, and therefore an inner liner layer 4 of butyl rubber having a large heat buildup will immediately peel off and break. Even if repairing the puncture before the reinforcing rubber layer 5 breaks, there was the problem that sometimes the tire could no longer be reused.